Because their money is in various types of trusts that are completely untraceable and figuring out how much they have or do not have is nearly impossible. Many of these trusts were formed and blessed by the king/queen of whatever nation they're housed in and they allow the R's to make tons tas free and to distribute that money to other trusts. If someone sues a Rothschild they quickly find out that they have no personal assets which can be attached. Even the homes they live in are owned by the family and corporate trusts.

Suffice it to say they're worth plenty but most do not know where or how it is distributed to them. But they never seem to go hungry or without anything at all.